For starters — as I reported back in January on Engadget — the design of the phone is set to radically change (“a completely redesigned handset”). Our sources say the new model (or at least one of the new designs in testing) looks “more like the iPod touch than the iPhone 4.” The phone will be thinner than the iPhone 4, and may have a “teardrop” shape which goes from thick to thin (something along the lines of the MacBook Air profile).

Now, keep in mind that this info isn’t fact — we’re getting lots of threads from lots of places and trying to make sense of the noise. The versions of devices our sources are seeing could be design prototypes and not production-ready phones. Still, there are strong indications that Apple will surprise a public that’s expecting a bump more along the lines of the 3G to 3GS — and this is some insight into where those designs might be headed. We’re working on a couple of other intriguing pieces of information concerning future Apple products… so stay tuned for much, much more.